Improve Text Generation doc (#18788)

* fix args for bram search decoding in generation utils

* fix missing PAD token in gpt2

* add PAD EOS change to TF

* Update src/transformers/generation_tf_utils.py
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

* Update src/transformers/generation_utils.py
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

* Update src/transformers/generation_utils.py
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

src/transformers/generation_tf_utils.py

@@ -2113,7 +2113,7 @@ class TFGenerationMixin:
         >>> tokenizer = AutoTokenizer.from_pretrained("gpt2")
         >>> model = TFAutoModelForCausalLM.from_pretrained("gpt2")
 
-        >>> # set pad_token_id to eos_token_id because GPT2 does not have a EOS token
+        >>> # set pad_token_id to eos_token_id because GPT2 does not have a PAD token
         >>> model.config.pad_token_id = model.config.eos_token_id
 
         >>> input_prompt = "Today is a beautiful day, and"

src/transformers/generation_utils.py

@@ -1139,7 +1139,7 @@ class GenerationMixin:
         >>> sentence = "Paris is one of the densest populated areas in Europe."
         >>> input_ids = tokenizer(sentence, return_tensors="pt").input_ids
 
-        >>> outputs = model.generate(input_ids)
+        >>> outputs = model.generate(input_ids, num_beams=5)
         >>> tokenizer.batch_decode(outputs, skip_special_tokens=True)
         ['Paris ist eines der dichtesten besiedelten Gebiete Europas.']
         ```"""
@@ -1635,7 +1635,7 @@ class GenerationMixin:
         >>> tokenizer = AutoTokenizer.from_pretrained("gpt2")
         >>> model = AutoModelForCausalLM.from_pretrained("gpt2")
 
-        >>> # set pad_token_id to eos_token_id because GPT2 does not have a EOS token
+        >>> # set pad_token_id to eos_token_id because GPT2 does not have a PAD token
         >>> model.config.pad_token_id = model.config.eos_token_id
 
         >>> input_prompt = "It might be possible to"